It’s all in the instincts. A well-fed cat may actually just look at the mouse and ignore it altogether. Cats are great hunters but when they stay indoors then they don’t primarily need to hunt around. They may just loose their “killer instincts” and may become too lazy to chase a mouse. Although this theory is quite prominent but still it can’t be generalized; and indoor cats still hunt and run after the mouse.
One important point in case of cats is that they love to prey on anything that’s moving. If you own a cat, just give it a try by throwing wad of paper in front of feline and chances are pretty high that the cat will pounce upon it. The cats that stay mostly outdoors are good hunters compared to the ones who stay indoor. The outdoor cats chase and kill the mouse and eventually eat it to quench their hunger.
One more interesting trait that has been noticed in case of cat’s behavior is that they love to be playful when they hunt or chase the mouse. Once they chase and catch the mouse, they tend to play with their prey until it’s dead or shows no movement. In such cases if the cat has kittens to feed, it may just take the bounty to her young ones so that they can feed upon it. Mother cats may also take half alive mouse to their kittens so that they can play with it and learn to hunt.
The cats are agile hunter by birth and may wait for their prey for hours together sitting motionless. Once the mouse is visible and in reach, they will chase it and eventually catch it if all goes well. Sometimes, we observe that after chasing and killing the mouse they will just bring it to their owner to probably show the catch.